1. Field of the Invention
The present invention relates to a laundry dryer, and more particularly, to a laundry dryer having a device that can reduces vibration and noise, which are generated by laundry rotating in a dry drum, as well as vibration and noise, which are generated by interferences between a rotational belt disposed on an outer circumference of the dry drum and a head portion of a coupling member inserted in the dry drum.
2. Description of the Related Art
Generally, a drum-type laundry dryer is designed to perform the drying operation while rotating laundry loaded in a dry drum. The laundry rotates and drops by the rotation of the laundry drum. High-temperature dry air introduced into the dry drum is mixed with the laundry to vaporize the moisture soaked in the laundry. The laundry dryer may be classified into a condenser-type dryer and an exhaust-type dryer. The former is designed such that the air in the dry drum is directed to a condenser and a heater and is then returned to the dry drum. That is, the air circulates in the dryer without being exhausted out of the dryer. The latter is designed such that the air in the dry drum is directed to the condenser so that the moisture contained in the air can be eliminated and is then exhausted out of the dryer.
Describing in more detail, in the condenser-type dryer, the air circulating in the dryer absorbs the moisture from the laundry loaded in the drum and passes through the condenser to be lowered in its temperature by a heat-exchange. As the temperature of the air is lowered, the moisture contained in the air is condensed. The condensed water is pumped out by an condensing pump and is then exhausted to an exterior side.
In the exhaust-type dryer, high-temperature high-moisture air absorbing moisture from the laundry in the drum is exhausted out of the dryer via a lint filter.
In both the exhaust-type and condenser type dryers, as the laundry lifts and drops by the rotation of the drum, heat-exchange is briskly incurred.
The structure of the convention drum and dryer operation is disclosed in U.S. Pat. No. 6,698,107 assigned to an applicant of this application.
However, in the prior laundry dryer, noise is incurred as hard objects such as zippers and buttons that are attached on the laundry and coins in pockets collide with an inner wall of the drum in the course of the drum and the laundry rotate. Furthermore, the drum functions as a resonance drum, the incurred noise may be boosted.
To solve this problem, the drum is designed to be thick. In this case, since the weight of the drum is increased, making it difficult to perform the assembling process. Furthermore, the thick drum causes the manufacturing costs to be increased.
Meanwhile, a belt is mounted on an outer circumference of the dry drum to rotate the dry drum. The belt is connected to a motor shaft of a driving motor. A lift for lifting the laundry is mounted in the dry drum. That is, the lift is fixed on an inner circumference of the dry drum by a coupling member penetrating the dry drum from an outer side. In this case, the belt interferes with a head portion of the coupling member extending from the outer circumference of the dry drum, as a result of which the belt may be damaged. Sometimes, the belt may be broken, thereby stopping the rotation of the dry drum and allowing only the motor to rotate. As a result, power consumption and maintenance costs are increased.
In addition, the interference between the belt and the head portion of the coupling member may cause the additional noise.